Chemical liquid injection system detecting attachment and detachment of chemical liquid syringe to and from chemical liquid injection device

ABSTRACT

The present invention includes mount-detecting means  131  placed at the position of liquid injector  100  where liquid syringe  200  is mounted and removed. This allows mount-detecting means  131  to detect the mount and dismount of liquid syringe  200  on and from liquid injector  100 , and the detection result can be output to notify the operator, and/or the operation of piston actuating mechanism  116  can be controlled in accordance with the detection result. Thus, the present invention provides liquid injector  100  which can detect the mount and dismount of liquid syringe  200  on and from liquid injector  100.

TECHNICAL FIELD

The present invention relates to a liquid injection system for injectingliquid into a patient by relatively moving a cylinder member and apiston member of a liquid syringe that is mounted on a liquid injector,and more particularly relates to a liquid injection system in which aliquid syringe is mounted on a liquid injector by a cylinder adapter.

BACKGROUND ART

Presently available imaging diagnostic apparatus for capturingfluoroscopic images of patients include CT (Computed Tomography)scanners, MRI (Magnetic Resonance Imaging) apparatus, PET (PositronEmission Tomography) apparatus, ultrasonic diagnostic apparatus,angiography apparatus, and MRA (MR Angiography) apparatus.

When such imaging diagnostic apparatus are used to capture afluoroscopic image of a patient, it is occasionally practiced to injecta liquid such as a contrast media or a saline solution into the patient.A liquid injector for automatically injecting a liquid into a patienthas been commercially available. Such a liquid injector has a maininjector body on which a liquid syringe is removably mounted.

The liquid syringe has a hollow cylinder member filled with a liquid anda cylindrical piston member slidably inserted in the cylinder member.Generally, the cylinder member has an annular cylinder flange disposedon the outer circumferential edge of the rear end thereof, and thepiston member has an annular piston flange disposed on the outercircumferential edge of the rear end thereof.

When the liquid injector is in use, the cylinder member of the liquidsyringe which is filled with the liquid is connected to the patient byan extension tube, and the liquid syringe is mounted on the maininjector body. In general liquid injectors, the main injector body has aconcave defined in its upper surface complementary in shape to thecylinder member of the liquid syringe and its cylinder flange.Therefore, the liquid syringe is held on the main injector body when thecylinder member and the cylinder flange are placed in the concave.

The liquid injector also has a piston actuating mechanism for holdingthe piston flange independently of the cylinder member and sliding thepiston member into and out of the cylinder member. When the pistonmember is pushed into the cylinder member, the liquid in the cylindermember can be injected into the patient. When the piston member ispulled out of the cylinder member, the cylinder member can draw theliquid from a liquid container.

Generally, in order to allow the liquid injector to hold various typesof liquid syringes having various shapes, the concave defined in theupper surface of the main injector body is shaped to be able to receivethe cylinder member of the liquid syringe having the maximum size.Liquid syringes having sizes other than the maximum size are combinedwith respective dedicated cylinder adapters and placed in the concave inthe main injector body.

Cylinder adapters generally have concaves defined in their uppersurfaces complementary in shape to the cylinder members of the liquidsyringes and their cylinder flanges as the main injector body does. Thecylinder members of the liquid syringes and their cylinder flanges areheld in the concaves in the cylinder adapters. The cylinder adaptershave lower surfaces whose outer profiles are similar to the outerprofile of the cylinder member of the liquid syringe having the maximumsize and the cylinder flange thereof, and are placed in the concave inthe main injector body.

Liquid injectors constructed as described above have been invented bythe inventor of the present invention and filed for patent (see, forexample, Patent documents 1 and 2 shown below):

LIST OF REFERENCES

Patent document 1: Japanese laid-open patent publication No. 2002-11096.

Patent document 2: Japanese laid-open patent publication No.2002-102343.

The above liquid injectors hold a liquid syringe when the cylindermember is directly placed in the concave in the main injector body orwhen the cylinder adapter with the cylinder member mounted in itsconcave is placed in the concave in the main injector body.

However, the liquid syringe may not be mounted suitably on the liquidinjector, for example when the liquid syringe mounted on the liquidinjector falls off during the injection operation. The operator needs tocheck appropriately the liquid syringe suitably mounted on the liquidinjector to prevent the fall, which is difficult to achieve in reality.

DISCLOSURE OF INVENTION

The present invention has been made in view of the abovementionedproblem, and it is an object thereof to provide a liquid injectionsystem which can detect mount and dismount (i.e. attachment anddetachment) of a liquid syringe on and from a liquid injector.

The liquid injection system according to the present invention includesa liquid syringe and a liquid injector. The liquid syringe has acylinder member and a piston member which is slidably inserted into thecylinder member. The cylinder member is filled with a liquid in advance.The liquid injector includes a cylinder holding mechanism, a pistonactuating mechanism, and a mount-detecting means.

The cylinder holding mechanism receives the cylinder member of theliquid syringe mounted removably thereon. The piston actuating mechanismrelatively moves the piston member with respect to the cylinder memberof the liquid syringe. The mount-detecting means detects contact andseparation of the cylinder member when it is mounted on and removed fromthe cylinder holding mechanism, respectively.

Thus, in the liquid injection system of the present invention, theliquid injector can detect the mount and dismount of the liquid syringe,so that the detection result can be output to notify the operator, orthe operation of the piston actuating mechanism can be controlled inaccordance with the detection result, for example.

Various means referred to in the present invention may be arranged toperform their functions, and may comprise dedicated hardware forperforming a predetermined function, a data processing apparatus whosepredetermined function is given by a computer program, a predeterminedfunction performed by a data processing apparatus according to acomputer program, or a combination thereof.

Various components referred to in the present invention do not need tobe a separate entity. Rather, these components may be constructed as onecomponent, a certain component may be part of another component, or acertain component may have a portion overlapping a portion of anothercomponent.

Certain terms with respect to forward, rearward, upward, downward,leftward, and rightward directions which will be referred to in thedescription are used for convenience only to simplify the illustrationof relative positional relationships of various parts, and should not beinterpreted as being limited to directions that are involved when theliquid injection system is manufactured and used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the manner in which a liquidsyringe is mounted on a liquid injector by a cylinder adapter of aliquid injection system according to the present invention;

FIG. 2 is a perspective view showing an exterior appearance of theliquid injector;

FIG. 3 is a perspective view showing an exterior appearance of theliquid injection system;

FIGS. 4 a and 4 b are perspective views showing the manner in which aliquid syringe is mounted on a cylinder adapter;

FIGS. 5 a and 5 b are perspective views showing the manner in which aliquid syringe is mounted on a cylinder adapter;

FIG. 6 is a block diagram illustrating the circuitry of the liquidinjection system;

FIGS. 7 a and 7 b are vertical cross-sectional views showing the mannerin which a liquid syringe is direct mounted on an injection head of aliquid injector;

FIGS. 8 a and 8 b are vertical cross-sectional views showing the mannerin which a liquid syringe is mounted on a cylinder adapter;

FIGS. 9 a and 9 b are vertical cross-sectional views showing the mannerin which a liquid syringe is mounted on an injection head by a cylinderadapter;

FIG. 10 is a flow chart illustrating the operation of the liquidinjector; and

FIG. 11 is a perspective view of an injection head according to amodification.

BEST MODE FOR CARRYING OUT THE INVENTION Configuration of Embodiment

As shown in FIGS. 1 to 3, liquid injection system 1000 according to thepresent invention has liquid injector 100, liquid syringe 200, MRIapparatus 300 as an imaging diagnostic apparatus, and cylinder adapter400. When a fluoroscopic image of a patient (not shown) is to becaptured by MRI apparatus 300, liquid injector 100 injects a liquid suchas a contrast media or a saline solution from liquid syringe 200 intothe patient.

As shown in FIG. 3, MRI apparatus 300 comprises imaging unit 301 as animage capturing mechanism and control unit 302 which are connected toeach other by a wired communication network (not shown). Imaging unit301 captures a tomographic image of the patient, and control unit 302controls operation of imaging unit 301.

As shown in FIG. 1, liquid syringe 200 comprises cylinder member 210 andpiston member 220 slidably inserted in cylinder member 210. Cylindermember 210 has hollow cylindrical cylinder casing 211 with conduit 212disposed on a closed distal end thereof.

Cylinder casing 211 of cylinder member 210 has an open end remote fromthe closed distal end thereof, and piston member 220 is inserted intocylinder casing 211 through the open end. Cylinder casing 211 hascylinder flange 213 disposed on the outer circumferential edge of theopen end thereof. Piston member 220 has piston flange 221 disposed onthe outer circumferential edge of an end thereof.

As shown in FIG. 2, liquid injector 100 comprises injection control unit101 and injection head 110 as a main injector body which are separatefrom each other. Injection control unit 101 and injection head 110 areconnected to each other by communication cable 102.

Injection head 110 actuates liquid syringe 200 mounted thereon to injecta liquid therefrom into the patient. Injection control unit 101 controlsthe operation of injection head 110. Injection control unit 101 houses amicrocomputer 130 therein, and is connected to control unit 302 of MRIapparatus 300 by the wired communication network 312.

As shown in FIG. 2, injection control unit 101 has console panel 103,touch panel 104 as a display panel, and speaker unit 105 which aredisposed on the front face of a unit housing 106. Separate controllerunit 107 is connected to injection control unit 101 by connector 108.

Injection head 110 is mounted on the upper end of caster stand 111 bymovable arm 112. As shown in FIG. 1, injection head 110 includes headbody 113 as a cylinder holding structure having semi-cylindricalgroove-like concave 114 defined in an upper surface thereof forreceiving liquid syringe 200 removably mounted therein.

Injection head 110 has piston actuating mechanism 116 positionedrearwardly of concave 114 for holding and sliding piston flange 221, andflange holding mechanism 120 disposed forwardly of concave 114 forremovably holding cylinder flange 213 of liquid syringe 200.

Piston actuating mechanism 116 has an ultrasonic motor (not shown) as adrive source which does not produce a magnetic field. The ultrasonicmotor is made of a nonmagnetic material such as phosphor bronze alloy(Cu+Sn+P), titanium alloy (Ti−6Al−4V), magnesium alloy (Mg+Al+Zn), orthe like.

Liquid injection system 1000 has liquid syringes 200 available for usein various different sizes. Only liquid syringe 200 having the maximumsize is directly mounted in concave 114 in injection head 110, and otherliquid syringes 200 having sizes other than the maximum size areselectively mounted in concave 114 with respective dedicated cylinderadapters 400.

Flange holding mechanism 120 of liquid injector 100 is of a structurefor holding cylinder flange 213 of a liquid syringe having the maximumsize. Cylinder adapter 400 has an outer profile which is of the sameshape as liquid syringe 200 having the maximum size so that cylinderadapter 400 can be held by concave 114 and flange holding mechanism 120of injection head 110.

Flange holding mechanism 120 has a pair of laterally spaced movableholders 121 and a single stationary holder 122 disposed between movableholders 121. Movable holders 121 and stationary holder 122 are disposedin an annular pattern. Stationary holder 122 has a semi-arcuate shapewhich is upwardly concave, and movable holders 121, each of a quarterarcuate shape, are disposed one on each side of stationary holder 122.

Movable and stationary holders 121, 122 have respective grooves definedin inner concave edges thereof. Cylinder flange 213 of liquid syringe200 having the maximum size engages removably in the grooves in movableand stationary holders 121, 122. Movable holders 121 are pivotallysupported by respective holder pivot support mechanisms (not shown) forvertical angular movement between an open position in which movableholders 121 are open upwardly for allowing cylinder flange 213 to beinserted into the grooves in movable and stationary holders 121, 122,and a closed position in which cylinder flange 213 is retained at itsopposite sides in the grooves in movable and stationary holders 121,122.

When movable holders 121 are in the closed position, their lower endsare positioned downwardly of the axes of the holder pivot supportmechanisms and their upper ends are positioned upwardly of the axes ofthe holder pivot support mechanisms. Movable holders 121 are constructedas components separate from head body 113. However, movable holders 121may be integrally formed with head body 113.

Injection head 110 has press switch 131 as a mount-detecting means nearthe bottom of concave 114. As shown in FIGS. 7 a and 7 b, press switch131 detects liquid syringe 200 having the maximum size installed inconcave 114 when liquid syringe 200 comes into contact with switch 131.

As shown in FIG. 6, the respective components of liquid injector 100 areconnected to microcomputer 130 which controls the respective componentsaccording to a computer program installed therein. In a similar way,control unit 302 of MRI apparatus 300 is formed of a computer unit whichcontrols the operation of imaging unit 301 according to a computerprogram installed therein.

In imaging diagnostic system 1000 of the embodiment, microcomputer 130of liquid injector 100 and control unit 302 of MRI apparatus 300communicate various types of data with each other to controlcoordination of various operations thereof. Thus, microcomputer 130 ofliquid injector 100 serves as various means such as an actuating controlmeans, and control unit 302 of MRI apparatus 300 serves as various meanssuch as an imaging control means.

More specifically, microcomputer 130 of liquid injector 100 detects themount and dismount of liquid syringe 200 on and from injection head 110by press switch 131 and outputs the detection result as display on touchpanel 104. Microcomputer 130 enables the operation of piston actuatingmechanism 116 while it detects the mount of liquid syringe 200 oninjection head 110, and it disables the operation thereof while it doesnot detect the mount.

Microcomputer 130 of liquid injector 100 transmits the abovementioneddetection result of the mount or removal of liquid syringe 200 tocontrol unit 302 of MRI apparatus 300. In response to that, control unit302 enables the operation of imaging unit 301 when it receives thedetection result indicating that liquid syringe 200 is mounted, and itdisables the operation thereof when it receives the detection resultindicating that liquid syringe 200 is not mounted.

The various means of liquid injector 100 and MRI apparatus 300 asdescribed above are realized by using hardware such as touch panel 104as required. However, the main part is realized by microcomputer 130 andimaging unit 302 performing various operations according to the computerprograms installed therein.

Cylinder adapter 400 is prepared for each of liquid syringes 200 havingsizes other than the maximum size. As shown in FIGS. 4 a, 4 b, 5 a, and5 b, cylinder adapter 400 has adapter body 401 curved in U-shape.Adapter body 400 has concave 402 defined in an upper surface thereof andhaving a U-shaped cross-section for receiving cylinder member 210 ofliquid syringe 200 removably mounted therein from above. Cylinderadapter 400 has flange holding mechanism 410 positioned rearwardly ofconcave 402 for holding cylinder flange 213.

Flange holding mechanism 410 of cylinder adapter 400 has the similarstructure to that of flange holding mechanism 120 of liquid injector100, and has a pair of laterally spaced movable holders 411 and a singlestationary holder 412. Movable and stationary holders 411 and 412 haveconcave grooves 413 defined in inner surfaces thereof. Cylinder flange213 of liquid syringe 200 removably engages in concave grooves 413.

Movable holders 411 are pivotally supported by respective holder pivotsupport mechanisms 414 for vertical angular movement between an openposition in which movable holders 411 are open upwardly for allowingcylinder flange 213 to be inserted into concave grooves 413 in movableand stationary holders 411, 412, and a closed position in which cylinderflange 213 is retained at its opposite sides in concave grooves 413 inmovable and stationary holders 411, 412.

When movable holders 411 are in the closed position, their lower endsare positioned downwardly of the axes of holder pivot support mechanisms414 and their upper ends are positioned upwardly of the axes of holderpivot support mechanisms 414. Stationary holder 412 is formed integrallywith adapter body 401. However, stationary holder 412 may be constructedas a component separate from adapter body 401.

Adapter body 401 have a lower surface whose outer profile is of the sameshape as cylinder member 210 of liquid syringe 200 having the maximumsize, and has adapter flange 416 forwardly of flange holding mechanism120 in its lower surface. The outer profile of adapter flange 416 is ofthe same shape as cylinder flange 213 of liquid syringe 200 having themaximum size.

As shown in FIGS. 4 a, 4 b, 5 a, and 5 b, movable holders 411 ofcylinder adapter 400 protrude outward when they are placed in the openposition. Thus, cylinder adapter 400 with its movable holders 411 in theclosed position is mounted in concave 114 of liquid injector 100, butcylinder adapter 400 with its movable holders 411 in the open positionis not mounted in concave 114.

Cylinder adapter 400 has throughhole 418 formed near the bottom ofconcave 402 and contact-transfer member 419 supported movably inthroughhole 418. More specifically, as shown in FIGS. 8 a, 8 b, 9 a, and9 b, throughhole 418 of cylinder adapter 400 is formed at the positioncorresponding to press switch 131 of injection head 110.Contact-transfer member 419 is biased to protrude into concave 402 fromthroughhole 418 by a bias mechanism (not shown) such as a plate spring.

When the adapter body with no cylinder member 210 mounted thereon isinstalled in head body 113, contact-transfer member 419 is biased to theposition where it is not in contact with press switch 131. When theadapter body with cylinder member 210 mounted thereon is installed inhead body 113, contact-transfer member 419 is moved to the positionwhere it is in contact with press switch 131.

Adapter body 401 and movable holders 411 are made of engineering plasticor the like, and holder pivot support mechanisms 414 are made of anonmagnetic material such as phosphor bronze alloy (Cu+Sn+P), titaniumalloy (Ti−6Al−4V), magnesium alloy (Mg+Al+Zn), or the like. Therefore,cylinder adapter 400 is made of nonmagnetic materials.

Operation of Embodiment

The liquid injection system 1000 according to the present inventionoperates as follows: The operator selects liquid syringe 200 that issuitable for a liquid that is to be injected into the patient, andconnects conduit 212 of selected liquid syringe 200 to the patient withan extension tube (not shown).

If selected liquid syringe 200 is of the maximum size which does notrequire the use of cylinder adapter 400, then cylinder member 210thereof is directly placed in concave 114 in injection head 110, andcylinder flange 213 is held by flange holding mechanism 120 and pistonmember 220 is simultaneously gripped by cylinder actuating mechanism116.

In that case, when liquid syringe 200 is inserted from above intoconcave 114 of injection head 110, movable holders 121 placed in theopen position are automatically turned into the close position. Cylinderflange 213 is retained at its opposite sides in movable holders 121 andat its lower portion in stationary holder 122.

As shown in FIG. 7 b, at this point, cylinder member 210 comes intocontact with press switch 131 protruding into concave 114 of injectionhead 110, so that press switch 131 detects the mount of liquid syringe200 on injection head 110.

If selected liquid syringe 200 is of a size other than the maximum size,then, as shown in FIG. 8, liquid syringe 200 is mounted on cylinderadapter 400, and then placed together with cylinder adapter 400 oninjection head 110.

More specifically, if movable holders 411 of cylinder adapter 400 are inthe open position, then when cylinder member 210 of liquid cylinder 200is inserted from above into concave 402 to insert cylinder flange 213into grooves 413, movable holders 411 are automatically turned into theclosed position by being pressed by cylinder member 210.

Cylinder flange 213 of liquid syringe 200 is now retained at itsopposite sides by movable holders 411 of cylinder adapter 400, andretained at its lower side by stationary holder 412.

At this point, as shown in FIG. 8 b, cylinder member 210 comes intocontact with contact-transfer member 419 protruding into concave 402 ofcylinder adapter 400, so that contact-transfer member 419 is moved tothe position where it is flush with the outer surface of adapter body401.

Then, liquid syringe 200 is inserted, together with cylinder adapter400, from above into concave 114 in injection head 110. Movable holders121 that are in the open position are automatically turned into theclosed position. Adapter flange 416 is now retained at its oppositesides by movable holders 121, and retained at its lower side bystationary holder 122.

At this point, as shown in FIG. 9 a, contact-transfer member 419 ofcylinder adapter 400 comes into contact with press switch 131 protrudinginto concave 112 of injection head 110. Thus, press switch 131 detectsthe mount of liquid syringe 200 on injection head 110.

When liquid syringe 200 having the size other than the maximum size isused, it is possible that, as shown in FIG. 9 b, cylinder adapter 400 ismounted on injection head 110 and then liquid syringe 200 is mounted onand removed from cylinder adapter 400. In that case, as shown in FIG. 9b, when liquid syringe 200 is removed from cylinder adapter 400 mountedon injection head 100, contact-transfer member 419 of cylinder adapter400 is moved to the position where it is not detected by press switch131, so that press switch 131 detects liquid syringe 200 not mounted oninjection head 110.

Referring to FIG. 10, when press switch 131 detects the mount of liquidsyringe 200 on injection head 110 as described above (step S1),microcomputer 130 of liquid injector 100 outputs the display of aguidance message as “Syringe mounted” on touch panel 104 (step S2).

As shown in FIG. 7 a or FIG. 8 b or FIG. 9 b, when cylinder member 210of liquid syringe 200 is not mounted in concave 112 of injection head110, microcomputer 130 outputs the display of a guidance message as“Syringe not mounted” on touch panel 104 in accordance with thedetection result of press switch 131 (steps S1, S3).

While presses switch 131 detects liquid syringe 200 not mounted (stepsS1, S3), if the operator makes entry to start the injection with consolepanel 103 and/or touch panel 104 (step S4), an error guidance as “Checkmount of syringe” is output as display on touch panel 104 (step S5).

On the other hand, while press switch 131 detects the mount of liquidsyringe 200 on injection head 110 as described above (steps S1, S2), ifthe operator makes entry to start injection with console panel 103and/or touch panel 104 (step S6), liquid injector 100 transmits data forstarting injection to control unit 302 of MRI apparatus 300 (step S7).

While control unit 302 receives no data for starting injection fromliquid injector 100, it disables the operation of imaging unit 301. Whenit receives data for starting injection, it enables the operation ofimaging unit 301. In that state, if the operator makes entry to startimaging, control unit 302 transmits data for starting imaging back toliquid injector 100 and starts imaging by imaging unit 301, for example,after it waits for a predetermined time period which is necessary for acontrast media to reach the affected area.

When liquid injector 100 receives the data for starting imaging from MRIapparatus 300 in response to the transmission of data for startinginjection as described above (steps S7, S8), it activates pistonactuating mechanism 116 to inject a liquid such as contrast media intothe patient from liquid syringe 200 (step S9).

At this point, microcomputer 130 of liquid injector 100 continuouslymonitors the detection of liquid syringe 200 by press switch 131 (stepS10). If the detection by press switch 131 is lost during the liquidinjection, it forcedly stops piston actuating mechanism 116 (step S12).

Since microcomputer 130 transmits data indicating the injection stop tocontrol unit 302 of MRI apparatus 300 (step S13), control unit 302 alsostops forcedly the imaging by imaging unit 301. In addition, an errorguidance as “Syringe not mounted appropriately. Check mount of syringe”is output as display on touch panel 104 (step S14), so that the operatorcan check the mount of liquid syringe 200 on injection head 110.

Effect of the Embodiment

In liquid injection system 1000 of the embodiment, press switch 131 isplaced at the position of liquid injector 100 where it can detect themount and dismount of liquid syringe 200, so that liquid injector 100can detect the mount and dismount of liquid syringe 200 by press switch131.

The operator is notified of the detection result by the display outputon tough panel 104, so that the operator can immediately recognizeliquid syringe 200 not mounted appropriately, for example. In addition,since microcomputer 130 controls and disables piston actuating mechanism116 while press switch 131 does not detect liquid syringe 200, it ispossible to prevent piston actuating mechanism 116 from being activatedwhile liquid syringe 200 is not mounted appropriately.

Even when press switch 131 detects liquid syringe 200 and pistonactuating mechanism 116 is activated, piston actuating mechanism 116 isforcedly stopped if press switch 131 loses the detection of liquidsyringe 200. Thus, piston actuating mechanism 116 can be automaticallystopped when liquid syringe 200 falls off from the appropriate position,for example.

Furthermore, since liquid injector 100 and MRI apparatus 300 communicatevarious data with each other to coordinate the various operations, MRIapparatus 300 does not perform imaging operation while press switch 131of liquid injector 100 does not detect liquid syringe 200, therebymaking it possible to prevent useless imaging operation.

Liquid syringe 200 having the maximum size can be directly mounted onliquid injector 100, and liquid syringes 200 having sizes other than themaximum size can be mounted by respective dedicated cylinder adapters400. In addition, cylinder adapter 400 has contact-transfer member 419movably supported at the position corresponding to press switch 131, sothat press switch 131 can detect mount and dismount of liquid syringe200 through cylinder adapter 400 as shown in FIG. 9 a.

Specifically, as shown in FIG. 8 b, even when liquid syringe 200 put oncylinder adapter 400 is mounted on and removed from liquid injector 100,this can be detected by press switch 131. As shown in FIG. 9 b, evenwhen liquid syringe 200 is mounted on and removed from liquid injector100 with cylinder adapter 400 put thereon, this can be detected by pressswitch 131. As a result, it is unnecessary to force the operator to usea particular use and the operator can easily use the liquid injectionsystem.

Since contact-transfer member 419 of cylinder adapter 400 is biased tothe position where it is not in contact with press switch 131 unlessliquid syringe 200 is mounted, press switch 131 can favorably detectmount and dismount of liquid syringe 200 through cylinder adapter 400.

Cylinder adapter 400 holds cylinder flange 213 by the pair of lateralmovable holders 411 which can be opened or closed, so that it can holdappropriately cylinder member 210 even when contact-transfer member 419is biased to protrude into concave 402.

Since injection head 110 holds cylinder flange 213 or adapter flange 416by the pair of lateral movable holders 121 which can be opened or closedin a similar manner, it can hold appropriately cylinder member 210 orcylinder adapter 400 even when press switch 131 is biased to protrudeinto concave 114.

When cylinder adapter 400 is not mounted on liquid injector 100, movableholders 411 can be turned. However, when cylinder adapter 400 is mountedon liquid injector 100, movable holders 411 are held in the closedposition. Thus, cylinder adapter 400 mounted on liquid injector 100 canreliably fix liquid syringe 200.

When movable holders 411 are held in the closed position, cylinderadapter 400 can be installed in liquid injector 100. However, whenmovable holders 411 are held in the open position, cylinder adapter 400cannot be installed in liquid injector 100. Consequently, cylinderadapter 200 can not be installed in liquid injector 100 insofar asliquid syringe 200 is incompletely held by movable holders 411.

When movable holders 411 of cylinder adapter 400 are in the closedposition, the lower ends of movable holders 411 are positioned below theaxes of holder pivot support mechanisms 414 and the upper ends ofmovable holders 411 are positioned above the axes of holder pivotsupport mechanisms 414. Therefore, when liquid cylinder 200 is insertedfrom above into cylinder adapter 400 with movable holders 411 in theopen position, movable holders 411 are automatically turned into theclosed position.

When liquid cylinder 200 is pulled upwardly from cylinder adapter 400with movable holders 411 in the closed position, movable holders 411 areautomatically turned into the open position. Thus, liquid syringe 200can easily and intuitively be placed in and removed from cylinderadapter 400. Movable holders 121 of liquid injector 100 and cylinderadapter 400 also operate in the same fashion, so that cylinder adapter400 can easily and intuitively be mounted on and removed from liquidinjector 100.

When cylinder actuating mechanism 116 presses piston member 220 ofliquid syringe 200, large stresses are applied to cylinder flange 213and adapter flange 416. However, since cylinder flange 213 and adapterflange 416 have their lower portions held by stationary holders 412,122, respectively, cylinder flange 213 and adapter flange 416 are firmlyretained in place.

With liquid injection system 1000, liquid injector 100 is used in thevicinity of MRI apparatus 300. Since the drive source of liquid injector100 comprises an ultrasonic motor made of a nonmagnetic material whichdoes not produce a magnetic field, and the components of cylinderadapter 400 are made of a nonmagnetic material, liquid injector 100 andcylinder adapter 400 can be used in the vicinity of MRI apparatus 300without any problems.

Modifications of Embodiment

The present invention is not in any way limited to the above-describedembodiment, but various changes and modifications may be made thereinwithout departing from the scope of the invention. For example, althoughit is assumed in the above embodiment that liquid injector 100 is usedin the vicinity of MRI apparatus 300, liquid injector 100 may also beused in the vicinity of a CT scanner or an angiography apparatus.

In the above embodiment, liquid syringe 200 having the maximum size isdirectly mounted on liquid injector 100 and liquid syringes 200 havingsizes other than the maximum size are selectively mounted on liquidinjector 100 with respective cylinder adapters 400. However, all liquidsyringes 200 may be selectively mounted on liquid injector 100 withrespective cylinder adapters 400.

In the above embodiment, contact-transfer member 419 of cylinder adapter400 is biased to the position where it is not in contact with pressswitch 131. However, it is possible that contact-transfer member 419 issimply movably supported and is moved by biasing of press switch 131.

In the above embodiment, one liquid syringe 200 is mounted in oneconcave 112 of injection head 110 by one cylinder adapter 400. However,as shown in FIGS. 11 a and 11 b, a plurality of liquid syringes 200 maybe mounted on injection head 140 having a plurality of concaves 114.

In the above embodiment, the detection result or the like by pressswitch 131 is output as display on touch panel 104 separate frominjection head 110. However, as shown in FIGS. 11 a and 11 b, the resultor the like may be output as display on display panel 141 providedtogether with injection head 140. In this case, the detection result,such as whether liquid syringe 200 is appropriately mounted or not, isoutput as display near the position where liquid syringe 200 is mounted,so that the operator can see the mounting state of liquid syringe 200more instinctively.

In the above embodiment, cylinder adapter 400 holds piston flange 213 byflange holding mechanism 410 which can be opened or closed, andinjection head 110 holds piston flange 213 or adapter flange 416 byflange holding mechanism 120 which can be opened or closed. However, theflange holding mechanism may have any structure as long as it canappropriately hold piston flange 213 or adapter flange 416.

1. A liquid injection system comprising a liquid syringe; and a liquidinjector; the liquid syringe including a cylinder member and a pistonmember slidably inserted into the cylinder member, and the liquidinjector including a cylinder holding mechanism for receiving thecylinder member of the liquid syringe mounted removably thereon and apiston actuating mechanism for relatively moving the piston member withrespect to the held cylinder member of the liquid syringe, wherein theliquid injector comprises mount-detecting means for detecting contactand separation of the cylinder member when the cylinder member ismounted on and removed from the cylinder holding mechanism,respectively.
 2. A liquid injection system according to claim 1, whereinthe cylinder holding mechanism comprises: a pair of left and rightmovable holders, each having an arc-shaped groove defined in an innersurface, to the groove of which a cylinder flange of the liquid syringewith its axis extending forwardly and rearwardly are removably engaged,and a holder pivot support mechanism for pivotally supporting each ofthe movable holders for vertical angular movement between an openposition in which the movable holders are open upwardly for allowing thecylinder flange to be inserted into the grooves and a closed position inwhich the cylinder flange is retained from left and right sides by thegrooves.
 3. A liquid injection system according to claim 1, wherein theliquid syringes of various sizes are provided, further comprising atleast one cylinder adapter for allowing the cylinder holding mechanismto hold the liquid syringe having a size other than the maximum size,wherein the cylinder holding mechanism directly receives the liquidsyringe having the maximum size mounted thereon and the liquid syringehaving a size other than the maximum size mounted thereon through thecylinder adapter, and the cylinder adapter comprises an adapter bodyhaving an outer surface held by the cylinder holding mechanism and aninner surface holding the cylinder member and a contact-transfer membersupported movably and moved to a position where the contact-transfermember is in contact with the mount-detecting means when the adapterbody with the cylinder member mounted thereon is installed in thecylinder holding mechanism.
 4. A liquid injection system according toclaim 3, wherein the contact-transfer member is biased to a positionwhere the contact-transfer member is not in contact with themount-detecting means when the adapter body with the cylinder member notmounted thereon is installed in the cylinder holding mechanism.
 5. Aliquid injection system according to claim 3, wherein the cylinderadapter includes: a pair of left and right movable holders, each havingan arc-shaped groove defined in an inner surface, to the groove of whichthe cylinder flange of the liquid syringe with its axis extendingforwardly and rearwardly are removably engaged, and a holder pivotsupport mechanism for pivotally supporting each of the movable holdersfor vertical angular movement between an open position in which themovable holders are open upwardly for allowing the cylinder flange to beinserted into the grooves and a closed position in which the cylinderflange is retained from left and right sides by the grooves.
 6. A liquidinjection system according to claim 3, wherein components of thecylinder adapter are made of a nonmagnetic material.
 7. A liquidinjection system according to claim 1, wherein the liquid injectorfurther includes a display panel for outputting as display the detectionresult of the mount-detecting means.
 8. A liquid injection systemaccording to claim 7, wherein the display panel is provided togetherwith at least one of the cylinder holding mechanism and the pistonactuating mechanism.
 9. A liquid injection system according to claim 1,wherein the liquid injector further includes drive control means forcontrolling the piston actuating mechanism to disable the operationthereof when the mount-detecting means detects no mount of the liquidsyringe.
 10. A liquid injection system according to claim 1, wherein theliquid injector further comprises: an imaging diagnostic apparatus forcapturing an image of a patient to whom a liquid is injected from theliquid syringe; and control means for controlling the imaging diagnosticapparatus to disable the operation thereof when the mount-detectingmeans detects no mount of the liquid syringe.
 11. A liquid injector usedfor the liquid injection system according to claim 1, comprising: acylinder holding mechanism for receiving a cylinder member of the liquidsyringe mounted removably thereon; a piston actuating mechanism forrelatively moving the piston member with respect to the held cylindermember of the liquid syringe; and mount-detecting means for detectingcontact and separation of the cylinder member when the cylinder memberis mounted on and removed from the cylinder holding mechanism,respectively.
 12. A cylinder adapter of the liquid injection systemaccording to claim 3, comprising: an adapter body having an outersurface held by the cylinder holding mechanism and an inner surfaceholding the cylinder member; and a contact-transfer member supportedmovably and moved to a position where the contact-transfer member is incontact with the mount-detecting means when the adapter body with thecylinder member mounted thereon is installed in the cylinder holdingmechanism.
 13. A liquid injection system comprising: a first liquidsyringe comprising a cylinder member and a piston member slidablyinserted into the cylinder member; and a liquid injector comprising acylinder holding mechanism for receiving the cylinder member of theliquid syringe mounted removably thereon, and a piston actuatingmechanism for moving the piston member relative to the cylinder memberwhen the cylinder member is held by the cylinder holding mechanism;wherein the liquid injector further comprises a switch that detectscontact and separation of the cylinder member when the cylinder memberis mounted on and removed from the cylinder holding mechanism,respectively.
 14. A liquid injection system according to claim 13,wherein the liquid injector further includes a computer for controllingthe piston actuating mechanism to disable the operation thereof when theswitch detects no mount of a liquid syringe.
 15. A liquid injectionsystem according to claim 13, wherein the liquid injector furthercomprises: an imaging diagnostic apparatus for capturing an image of apatient into whom a liquid is injected from the liquid syringe; and acomputer for controlling the imaging diagnostic apparatus to disable theoperation thereof when the switch detects no mount of the liquidsyringe.
 16. A liquid injector for use in the liquid injection systemaccording to claim 13, comprising: a cylinder holding mechanism forreceiving a cylinder member of the liquid syringe mounted removablythereon; a piston actuating mechanism for relatively moving the pistonmember with respect to the held cylinder member of the liquid syringe;and a switch that detects contact and separation of the cylinder memberwhen the cylinder member is mounted on and removed from the cylinderholding mechanism, respectively.
 17. A liquid injection systemcomprising: a first liquid syringe comprising a cylinder member and apiston member slidably inserted into the cylinder member; and a liquidinjector comprising a cylinder holding mechanism for receiving thecylinder member of the liquid syringe mounted removably thereon, and apiston actuating mechanism for moving the piston member relative to thecylinder member when the cylinder member is held by the cylinder holdingmechanism; wherein the liquid injector further comprises mount-detectingmeans for detecting contact and separation of the cylinder member whenthe cylinder member is mounted on and removed from the cylinder holdingmechanism, respectively.
 18. A liquid injection system according toclaim 17, wherein the cylinder holding mechanism comprises: a pair ofleft and right movable holders, each having an arc-shaped groove definedin an inner surface, the grooves of which are removably engaged by acylinder flange of the liquid syringe; and a holder pivot supportmechanism for pivotally supporting each of the movable holders forvertical angular movement between an open position in which the movableholders are open upwardly for allowing the cylinder flange to beinserted into the grooves and a closed position in which the cylinderflange is retained from left and right sides by the grooves.
 19. Aliquid injection system according to claim 17, further comprising asecond liquid syringe having a smaller size than the first liquidsyringe; and a cylinder adapter for allowing the cylinder holdingmechanism to hold the second liquid syringe; wherein the cylinderholding mechanism directly receives the first liquid syringe mountedthereon and receives the second liquid syringe mounted thereon throughthe cylinder adapter; and the cylinder adapter comprises: an adapterbody having an outer surface held by the cylinder holding mechanism andan inner surface holding the cylinder member; and a contact-transfermember that is supported movably and is moved to a position where thecontact-transfer member is in contact with the mount-detecting meanswhen the adapter body with the cylinder member mounted thereon isinstalled in the cylinder holding mechanism.
 20. A liquid injectionsystem according to claim 19, wherein the cylinder adapter furthercomprises: a pair of left and right movable holders, each having anarc-shaped groove defined in an inner surface, the grooves of which areremovably engaged by the cylinder flange of the liquid syringe; and aholder pivot support mechanism for pivotally supporting each of themovable holders for vertical angular movement between an open positionin which the movable holders are open upwardly for allowing the cylinderflange to be inserted into the grooves and a closed position in whichthe cylinder flange is retained from left and right sides by thegrooves.